Changes in gene expression during drying and imbibition of desiccation sensitive Magnolia ovata (A. St.-Hil.) spreng. seeds

ABSTRACT.Seeds collected at different maturation stages vary in physiological quality and patterns of protective antioxidant systems against deterioration. In this study we investigated the expression of genes that codify catalase (CAT), dismutase superoxide (SOD), and polyphenol oxidase (PPO) during the pre-and post-physiological maturation phases in whole seeds and in endosperms and embryos extracted from the seeds. Coffea arabica L. berries were collected at the green, yellowish-green, cherry, over-ripe, and dry stages, and the seeds were examined physiologically. The transcription levels of the genes were quantified by quantitative real-time polymerase chain reaction using coffee-specific primers. The highest level of SOD expression was observed in the endosperm at the cherry and over-ripe stages; in addition, these seeds presented the greatest physiological quality (assessed via germination test). The highest CAT3 transcript expression was observed at the green stage in whole seeds, and at the green and over-ripe stages in the embryos and endosperms. High expression of the PPO transcript was observed at the green and yellowish-green stages in whole seeds. In embryos and endosperms, peak expression of the PPO transcript was observed at the green stage; subsequently, peaks at the cherry and over-ripe stages were observed. We concluded that the expression patterns of the SOD and CAT3 transcripts were similar at the more advanced maturation stages, which corresponded to enhanced physiological seed quality. High expression of the PPO transcript at the over-ripe stage, also observed in the embryos and endosperms at the cherry stage, coincided with the highest physiological seed quality.

Section: Discussionmentioning

confidence: 99%

Gene expression of antioxidant enzymes and coffee seed quality during pre- and post-physiological maturity

Santos¹,

Caixeta²,

Clemente³

et al. 2014

“…However, it was observed that these genes are also expressed in endosperm, as well as observed in earlier studies of expression of β-tubulin (TUB) and endo-β-mannanase (MAN) genes in coffee seeds (Santos et al, 2015). The use of whole seeds in the RNA extraction may have resulted in a high embryonic RNA dilution, since the embryo's volume is estimated to 1/40 of the whole seed (José et al, 2009). In Figure 1, there is greater expression of the CaGA 3 transcript in cherry and overripe stages in whole seeds and endosperm.…”

Section: Resultsmentioning

confidence: 76%

“…In embryos, it was observed higher gene expression in raisin stage followed by dry stage. Molecular studies on seed maturation in model species revealed that maturation is primarily driven by three key genes: ABA INSENSITIVE 3 (ABI 3 ), FUSCA 3 (FUS3), LEAFY COLTILEDON 1 (LEC1) and LEAFY COLTILEDON 2 (LEC2) (To et al, 2006;José et al, 2009). In peas, it was observed that PsABI 3 is expressed in late stages, together with storage protein synthesis and delayed maturation (Radchuk et al 2010), showing the involvement of abscisic acid in the final maturation process.…”

Section: Resultsmentioning

confidence: 99%

“…In 2018 the country produced approximately 45 million bags (National Company Of Suppy -Conab, 2019), with Minas Gerais being the main producer state, with 54% of national production (Conab, 2019). Due to it's economic importance, research using molecular markers has been conducted to better understand metabolic reactions involved in the maturation of coffee seeds (José et al, 2009, Venglat et al, 2011.…”

Section: Introductionmentioning

confidence: 99%

See 1 more Smart Citation

Research Article GA3 and ABI3 gene expression in coffee seeds during maturation

Santos¹,

Rosa²,

Coelho³

et al. 2019

During maturation in seeds, metabolic processes dependent on gene expression are controlled by hormones, including abscisic acid and gibberellin. These hormones determine dormancy or the capacity for germination in seeds and may have different expression levels in the endosperm and embryo of coffee seeds. We quantified gene expression in the biosynthetic pathway of gibberellin and abscisic acid in different parts of Coffea arabica L. seeds in pre and post physiological maturity, in order to better understand the germination mechanisms of this species. Coffee fruits were harvested at green, yellowish-green, cherry, over-ripe and dry stages. For studies of gene expression, intact seeds were used in addition to endosperm and isolated embryos. The RNA from different tissues was extracted and treated with DNAse to synthesize cDNA. Transition levels of CaGA 3 (gibberellin) and CaABI 3 (abscisic acid) genes were quantified with qRT-PCR, using specific primers for coffee. Intact seeds at each phenological stage were submitted to germination tests, to evaluate the physiological quality of the seeds. Seed harvested at green and dry stages showed lower physiological ©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 18 (3): gmr18264 S.D.V.F. Rosa et al. 2 quality when compared to the other maturation stages, and germination at the green stage was close to zero. Greatest expression of CaGA 3 and CaABI 3 occurs in the endosperm of coffee seeds in cherry and over-ripe stages, with better physiological performance. There are differences in CaABI 3 and CaGA 3 gene expression in embryos and endosperm of the coffee seeds.

“…In the present study, it was seen that expression of the β-tubulin gene in whole seeds was lower than in the endosperm and embryo. According to José et al (2009), since the selected genes are expected to be expressed exclusively in the embryo, using whole seeds for RNA extraction may have resulted in considerable dilution of the embryonic RNA. The embryo volume is estimated as 1/40 of the whole coffee seed.…”

mentioning

confidence: 99%

Endo-β-mannanase and β-tubulin gene expression during the final phases of coffee seed maturation

Santos¹,

Clemente²,

Caixeta³

et al. 2015

ABSTRACT. Coffee seeds begin to develop shortly after fertilization and can take 6 to 8 months to complete their formation, a period during which all the characteristics of the mature seed are determined, directly influencing physiological quality. However, little is known about the molecular mechanisms that act during coffee seed maturation. The objective of the current study was to analyze expression of the β-tubulin (TUB) and endo-β-mannanase (MAN) genes during different phases at the end of development and in different tissues of Coffea arabica seeds. The transcription levels of the TUB and MAN genes were quantified in a relative manner using qRT-PCR in whole seeds, and dissected into embryos and endosperms at different developmental stages. Greater expression of MAN was observed in whole seeds and in endosperms during the green stage, and in the embryo during the over-ripe stage. High TUB gene expression was observed in whole seeds during the green stage and, in the embryos, there were peaks in expression during F.C. Santos et al. 11720©FUNPEC-RP www.funpecrp.com.br Genetics and Molecular Research 14 (4): 11719-11728 (2015) the over-ripe stage. In endosperms, the peak of expression occurred in both the green stage and in the cherry stage. These results suggest participation of endo-β-mannanase during the initial seed developmental stages, and in the stages of physiological maturity in the embryo tissues. TUB gene expression varied depending on the developmental stage and section of seed analyzed, indicating the participation of β-tubulin during organogenesis and coffee seed maturation.